Method and apparatus for aligning and securing an implant relative to a patient

ABSTRACT

A surgical instrument for implanting a prosthetic member. The instrument includes an orientation sensor that detects an initial orientation of the prosthetic member and an implanting orientation of the prosthetic member. The instrument further includes a memory module and an input device that receives a user input to transfer the initial orientation detected by the orientation sensor into the memory module for storage. Furthermore, the instrument includes an orientation feedback device that selectively provides an orientation feedback signal to a user. Moreover, the instrument includes a controller that causes the orientation feedback device to provide the orientation feedback signal when the implanting orientation detected by the orientation sensor is substantially equal to the initial orientation stored in the memory module.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 12/358,664 filed on Mar. 24, 2009, the disclosure of which isincorporated by reference herein in its entirety.

FIELD

The following relates to an implantable prosthesis and, moreparticularly, to a method and apparatus for aligning and securing animplant relative to a patient.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

Prosthetic joints can reduce pain due to arthritis, deterioration,deformation, and the like, and can improve mobility in the joint.Oftentimes, prosthetic joint assemblies include certain implantableprosthetic members that are fixed to the patient's anatomy. Forinstance, prosthetic hip joint assemblies often include an acetabularcup that is implanted and fixed to the patient's pelvis within theacetabulum. Once properly fixed to the pelvis, a liner may be receivedby the cup, and a femoral component may be moveably coupled within theliner.

Medical professionals often use impactor tools to implant and fixprosthetic members to the patient's anatomy. In the case of theacetabular cup, for instance, the surgeon may attach the cup to one endof the impactor tool and strike or otherwise apply a load to theimpactor tool to drive the cup into the acetabulum. Then, the impactortool is removed from the cup, leaving the cup in the desired locationand orientation within the acetabulum. Fasteners can also be used tofurther secure the cup to the pelvis.

To ensure that the prosthetic member will be oriented in a desiredposition during the implantation procedure, the surgeon typically movesthe impactor tool to a predetermined orientation relative to thepatient's anatomy and applies the load while maintaining the impactortool at this predetermined orientation. Certain measuring devices (e.g.,goniometers, etc.) have been proposed for these purposes. Specifically,in the case of implanting an acetabular cup, the surgeon might orientthe impactor tool such that the load axis is at a predeterminedinclination angle relative to the median plane of the patient's bodyand/or such that the load axis is at a predetermined anteversion anglerelative to the coronal plane of the patient's body. Thus, as the loadis applied to the impactor tool, the cup is driven along and fixed atthe predetermined inclination angle and/or the predetermined anteversionangle within the acetabulum.

However, measuring the orientation of the impactor tool in this mannercan be tedious, time consuming, inconvenient and inaccurate. Forinstance, surgeons typically must repeatedly measure the orientation ofthe impactor tool because applying one or more loads to the impactortool could move the impactor tool out of alignment with thepredetermined orientation. Additionally, the impactor tool can beimproperly aligned inadvertently due to human error. Furthermore, thegoniometer or other measurement device is oftentimes separate from theimpactor tool, and thus, the surgeon may need two hands to hold theimpactor tool and measure its orientation. Also, blood, tissue or othermatter can obscure the surgeon's ability to read the measurement device,which can lead to inaccuracies.

In addition, it can be difficult to know when the implantable prostheticmember has been driven far enough into bone or other tissue. Forinstance, a surgeon typically drives the acetabular cup far enough intothe acetabulum to seat the cup against cancellous bone. However, it canbe difficult to visually confirm that the cup is seated against thecancellous bone, and thus, surgeons typically rely on audible, tactile,or other non-visual cues to know the cup has been properly seated. Forexample, the surgeon repeatedly applies loads to the impactor tool toprogressively drive the cup into the acetabulum until the surgeon hearsa sound indicating that the cup is seated against cancellous bone. Inother cases, loads are applied to the impactor tool until the surgeonfeels a certain degree of bounce-back (i.e., displacement of the tool ina direction opposite to the vector of the impact force on the tool)indicating that the cup is seated against cancellous bone. However, theaccuracy of these methods can be improved.

SUMMARY

A surgical instrument is disclosed for implanting a prosthetic member.The instrument includes an orientation sensor that detects an initialorientation of the prosthetic member and an implanting orientation ofthe prosthetic member. The instrument further includes a memory moduleand an input device that receives a user input to transfer the initialorientation detected by the orientation sensor into the memory modulefor storage. Furthermore, the instrument includes an orientationfeedback device that selectively provides an orientation feedback signalto a user. Moreover, the instrument includes a controller that causesthe orientation feedback device to provide the orientation feedbacksignal when the implanting orientation detected by the orientationsensor is substantially equal to the initial orientation stored in thememory module.

In addition, a method of implanting a prosthetic member is disclosedthat includes detecting an initial orientation of the prosthetic member.The method also includes saving the initial orientation into a memorymodule as a result of receiving a user input. Furthermore, the methodincludes detecting an implanting orientation of the prosthetic memberand providing an orientation feedback signal when the implantingorientation of the prosthetic member is substantially equal to theinitial orientation.

In another aspect, a prosthesis implantation system for implanting aprosthetic member is disclosed that includes a trial prostheticacetabular cup defining a trial axis. The system also includes a primaryprosthetic acetabular cup defining a primary axis. Moreover, the systemincludes an impactor tool that removably couples to the primaryprosthetic acetabular cup and transfers a load along a load axis toimplant the primary prosthetic acetabular cup. In addition, the systemincludes a prosthesis implanting apparatus having a housing that definesa housing axis. The housing is removably coupled to the trial prostheticacetabular cup to position the housing axis at a known orientationrelative to the trial axis, and the housing is alternatively andremovably coupled to the impactor tool to position the housing axis at aknown orientation relative to the primary axis. The implanting apparatusfurther includes an orientation sensor that detects an initialorientation of the housing axis and an implanting orientation of thehousing axis relative to a direction of gravity. Additionally, theimplanting apparatus includes a memory module and an input device thatreceives a user input to transfer the initial orientation detected bythe orientation sensor into the memory module for storage. Furthermore,the implanting apparatus includes an orientation feedback device thatselectively provides an orientation feedback signal and a controllerthat causes the orientation feedback device to provide the orientationfeedback signal when the prosthesis implanting apparatus is coupled tothe impactor tool and when the implanting orientation is substantiallyequal to the initial orientation stored in the memory module.

In still another aspect, a method of implanting a primary prostheticacetabular cup is disclosed that includes removably coupling aprosthesis implanting apparatus with an orientation sensor to a trialprosthetic acetabular cup. The method further includes detecting aninitial orientation of the trial prosthetic acetabular cup with theorientation sensor and saving the initial orientation into a memorymodule as a result of receiving a user input. Furthermore, the methodincludes removing the prosthesis implanting apparatus from the trialprosthetic acetabular cup, removably coupling an impactor tool to theprimary prosthetic acetabular cup, and removably coupling the prosthesisimplanting apparatus to the impactor tool. In addition, the methodincludes detecting an implanting orientation of the prosthesisimplanting apparatus with the orientation sensor. Also, the methodincludes providing an orientation feedback signal when the implantingorientation is substantially equal to the initial orientation andimplanting the primary prosthetic acetabular cup at the initialorientation.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1 is a perspective view of an implanting assembly according to thepresent disclosure;

FIG. 2 is an exploded view of the implanting assembly of FIG. 1;

FIG. 3 is a perspective view of a patient, various reference planes, anda load axis of the implanting assembly of FIG. 1 relative to the variousreference planes of the patient;

FIG. 4 is a schematic view of the implanting assembly of FIG. 1;

FIG. 5 is a flowchart illustrating a method of implanting a prostheticimplant using the implanting assembly of FIG. 1;

FIG. 6 is a perspective view of a system for implanting a prosthesisaccording to various other exemplary embodiments of the presentdisclosure;

FIG. 7 is a perspective view of a prosthesis implanting apparatuscoupled to a trial prosthetic implant of FIG. 6, shown relative to apelvis;

FIG. 8 is a perspective view of the prosthesis implanting apparatus ofFIG. 7 coupled to a primary prosthetic implant of FIG. 6;

FIG. 9 is a section view of an impactor tool and an implanting apparatusof FIG. 6; and

FIG. 10 is a flow-chart illustrating a method of using the system ofFIG. 6. to implant the primary prosthetic implant.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses. Itshould be understood that throughout the drawings, correspondingreference numerals indicate like or corresponding parts and features.

Referring initially to FIGS. 1, 2 and 4, an exemplary embodiment of animplanting assembly 10 is illustrated. As will be discussed, theimplanting assembly 10 can be used for implanting any suitableprosthetic member 12. In the embodiments illustrated, the implantingassembly 10 is used to implant an acetabular cup 14. The acetabular cup14 can be of any suitable type. Specifically, the implanting assembly 10can be used to implant the acetabular cup 14 in a pelvis 15, within theacetabulum 17, of a patient 19 (FIG. 3). Thus, the implanting assembly10 can be used in a process for replacing a hip joint with a prosthetichip joint assembly.

The implanting assembly 10 can include an impactor tool 16, as shown inFIGS. 1 and 2. Generally, the impactor tool 16 can include an elongatedshaft 18 having an enlarged striking plate or head 20 at a proximal orfirst end 21. The shaft 18 can be longitudinally straight so as todefine an axis A. Alternately, the shaft 18 can be angled or curved toaccount for various anatomical shapes, surgical procedures, etc. Also,the enlarged head 20 can be substantially disk shaped and centered onthe axis A. The distal or second end 23 of the shaft 18 can include acoupling mechanism 25 as shown in phantom in FIG. 2. In someembodiments, the coupling mechanism 25 can include a thread (shown inphantom at 22) and a projection (shown in phantom at 24). The thread 22can enable the shaft 18 to be removably coupled to the acetabular cup 14in a corresponding threaded hole (not shown) in the acetabular cup 14.Also, the projection 24 can abut the acetabular cup 14 for transferringloads from the shaft 18 to the acetabular cup 14, as will be describedin greater detail below. It will be appreciated, however, that theimpactor tool 16 can be removably coupled to the acetabular cup 14 inany suitable fashion. Furthermore, the impactor tool 16 can be coupledto the acetabular cup 14 such that the shaft 18 and the acetabular cup14 both extend along the axis A.

As will be described, in order to implant the acetabular cup 14 in thepatient 19, a load F_(i) (FIG. 1) is applied to the head 20 of theimpactor tool 16. The surgeon can apply the load F_(i) with a mallet orother manual tool or with an automated tool. The shaft 18, in turn,transfers the load F_(i) along the axis A to the acetabular cup 14.Thus, the acetabular cup 14 is driven progressively into the acetabulum17 of the pelvis 15 of the patient 19 (FIG. 3) with each application ofthe load F_(i).

It will be appreciated that the load F_(i) transfers along the axis A tothe acetabular cup 14. Thus, the axis A corresponds to the load axis Aof the implanting assembly 10. It will also be appreciated that theimpactor tool 16 could include a curved or offset axis A and that theload F_(i) could be a rotational (i.e., angular) load without departingfrom the scope of the present disclosure.

The implanting assembly 10 can also include an implanting apparatus 26(FIGS. 1, 2 and 4). As shown in FIGS. 1 and 2, the implanting apparatus26 can include a housing 28. The housing 28 can be operatively coupledto the impactor tool 16. In some embodiments, the housing 28 can beremovably coupled to the shaft 18 of the impactor tool 16 such that theimplanting apparatus 26 extends substantially parallel to the axis A ofthe shaft 18. Specifically, the housing 28 can be substantiallycylindrical in shape with a passage 30 extending parallel and concentricto the axis A. The passage 30 receives the shaft 18 to fixedly couplethe housing 28 to the tool 16 in a fixed position relative to the axisA.

Furthermore, the housing 28 can include a seam 31 extendingsubstantially parallel to the axis A. The seam 31 separates a firstportion 32 a from a second portion 32 b of the housing 28. Thus, thefirst and second portions 32 a, 32 b can separate along the seam 31 toremove the housing 28 from the shaft 18. In some embodiments, thehousing 28 can have a clam shell design with a hinge (not shown) forhingeably attaching the first and second portions 32 a, 32 b of thehousing 28.

It will be appreciated that the housing 28 can fix to the shaft 18 inany suitable fashion, such as an interference fit, a taper lock betweenthe shaft 18 and the inner surface of the passage 30, and the like.Also, the shaft 18 can include a recess (not shown) that receives thehousing 28 such that the housing 28 is in a fixed position relative tothe axis A. Accordingly, the implanting apparatus 26 can removablycouple to preexisting, commercially available impactor tools 16, such asa RingLoc® Inserter (Part No. S313141) or a Magnum Inserter (Part No.313131), commercially available from Biomet, Inc. of Warsaw, Ind.

Furthermore, it will be appreciated that the implanting apparatus 26 canbe operatively coupled to the impactor tool 16 at any suitable location,including the head 20. It will also be appreciated that the seam 31 isoptional, and the implanting apparatus 26 can be configured to slide onto the shaft 18 in a direction substantially parallel to the axis A (seeFIG. 2). In addition, it will be appreciated that the implantingapparatus 26 can be integrally coupled to the impactor tool 16 such thatthe implanting apparatus 26 and the impactor tool 16 are monolithic. Forinstance, the implanting apparatus 26 can be incorporated directly inthe shaft 18 and/or the head 20 or any other suitable portion of thetool 16. Also, in some embodiments, the implanting apparatus 26 may beconfigured so that the apparatus 26 can be operably coupled to surgicaltools other than an implanting apparatus 26 for use in any othersuitable surgical procedure.

As shown in FIGS. 1, 2 and 4, the implanting apparatus 26 can include anorientation sensor 34. The orientation sensor 34 can be encapsulatedwithin the housing 28. In other embodiments, the orientation sensor 34is remote from the impactor tool 16. As will be discussed, theorientation sensor 34 can detect an actual orientation of the impactortool 16. More specifically, the orientation sensor 34 can be anaccelerometer that is able to detect the orientation of the impactortool 16 relative to a reference vector. In some embodiments, forinstance, the orientation sensor 34 detects the vector of the force ofgravity as a reference vector to detect the orientation of the impactortool 16 in space and relative to the patient. More specifically, theorientation sensor 34 detects the orientation of the axis A relative tothe vector of the force of gravity to detect the orientation of the tool16. In some embodiments, the orientation sensor 34 detects accelerationabout three separate orthogonal axes X, Y, Z (FIG. 3) in order to detectthe orientation of the impactor tool 16. Specifically, the orientationsensor 34 detects the orientation of the axis A relative to thecoordinate system X, Y, Z, as will be discussed in greater detail below.It will be appreciated that the orientation sensor 34 could be of anysuitable type other than an accelerometer. Also, it will be appreciatedthat the orientation sensor 34 can be an accelerometer that detectsaccelerations about any number (e.g., two) of axes.

Furthermore, the implanting apparatus 26 can include an orientationfeedback device 36. The feedback device 36 can be encapsulated withinthe housing 28, or in other embodiments, the feedback device 36 isremote from the housing 28. As will be described, the orientationfeedback device 36 can selectively provide an orientation feedbacksignal when the actual orientation of the impactor tool 16 issubstantially equal to a predetermined target orientation. Accordingly,as will be described in greater detail below, the feedback signalprovided by the orientation feedback device 36 automatically indicatesto the surgeon that the impactor tool 16 is in the target orientationsuch that the cup 14 can be properly positioned and implanted for addedconvenience and accuracy.

As represented in FIG. 4, the orientation feedback device 36 can includean audible feedback device 38 that emits an audible feedback signal. Forinstance, the audible feedback device 38 can include a speaker thatemits a preprogrammed sound when the impactor tool 16 is in the targetorientation. Furthermore, the orientation feedback device 36 can includea visual feedback device 40 that emits a visual feedback signal. Forinstance, the visual feedback device 40 can include one or more lights,such as LED lights, for emitting a preprogrammed light pattern when theimpactor tool 16 is in the target orientation. Additionally, theorientation feedback device 36 can include a tactile feedback devicethat selectively emits a tactile feedback signal when the impactor tool16 is in the target orientation. For instance, the tactile feedbackdevice 42 can include a vibration motor that selectively vibrates thehousing 28 and the impactor tool 16 when the impactor tool 16 is in thetarget orientation.

It will be appreciated that the orientation feedback device 36 canprovide any suitable feedback signal. Also, it will be appreciated thatthe feedback signal can be seen, heard, and felt simultaneously, andthis redundancy can increase accuracy and convenience. Thus, forinstance, if the visual feedback device 40 becomes covered in blood ortissue during use, the audible and/or tactile feedback device 38, 42 canadequately provide the feedback signal. However, it will be appreciatedthat the orientation feedback device 36 can include any number offeedback devices 38, 40, 42 or any other suitable feedback devicewithout departing from the scope of the present disclosure.

Moreover, as illustrated in FIG. 4, the implanting apparatus 26 caninclude a controller 46. The controller 46 can include variouscomponents, such as a microprocessor, memory, and the like. Thecontroller 46 can be encapsulated within the housing 28 of theimplanting apparatus 26, or the controller 46 can be at least partiallyprovided in a remote device, such as a separate computerized system. Thecontroller 46 can be in communication with the orientation sensor 34 andthe orientation feedback device 36. Accordingly, as will be discussed,the controller 46 causes the orientation feedback device 36 toselectively provide the respective orientation feedback signal(s) whenthe actual orientation of the impactor tool 16 detected by theorientation sensor 34 is substantially equal to a predetermined targetorientation of the impactor tool 16.

More specifically, with reference to FIG. 3, the medical professionalcan analyze the pelvis 15 and other anatomical features of the patient19 to determine a desired final, target location (i.e., target position,target orientation) for the acetabular cup 14 within the acetabulum 17,which will provide the patient 19 with sufficient stability, support,etc. The implanting assembly 10 can be used to properly orient theimpactor tool 16 such that the impactor tool 16 accurately drives theacetabular cup 14 toward this desired target location. For instance, thesurgeon can predetermine how the load axis A of the impactor tool 16should be oriented relative to a reference coordinate system such thatthe impactor tool 16 drives the acetabular cup 14 into the predeterminedtarget location. For purposes of discussion, this will be referred to asthe predetermined target orientation of the impactor tool 16. It will beappreciated that the target orientation of the impactor tool 16substantially corresponds to the trajectory or path of the acetabularcup 14 as it is driven into the acetabulum 17 by the impactor tool 16.

As shown in FIG. 3, the predetermined target orientation of the impactortool 16 can be the orientation of the load axis A relative to a medianplane P_(m) (i.e., sagittal plane) and a coronal plane P_(c) (i.e.,frontal plane) of the patient 19. Specifically, the surgeon candetermine a particular target inclination angle θ_(i) of the load axis Arelative to the median plane P_(m) and/or a particular anteversion angleθ_(a) of the load axis A relative to the coronal plane P_(c) necessaryfor the impactor tool 16 to drive the acetabular cup 14 into the finallocation within the pelvis 19.

It will be appreciated that the predetermined target orientation can beexpressed as a range of values. In some embodiments, for instance, thetarget inclination angle θ_(i) is at least approximately 35° and at mostapproximately 55°. Also, in some embodiments, the target anteversionangle θ_(a) is at least 10° and at most 20°. Furthermore, in someembodiments, the target inclination angle θ_(i) is approximately 45°.Additionally, in some embodiments, the target anteversion angle θ_(a) isapproximately 15°. As will be discussed, the implanting apparatus 26 caninclude one or more selectable preprogrammed target orientations, whichis/are stored in memory, and/or the predetermined target orientation canmanually set by the user.

It will be appreciated that the target inclination and anteversionangles θ_(i), θ_(a) can be determined for each individual patient 19according to the anatomical structure of the patient 19 and/or otherfactors. It will also be appreciated that the target inclination andanteversion angles θ_(i), θ_(a) can be of any suitable values.Furthermore, it will be appreciated that the implantation assembly 10can be used to detect and confirm any suitable orientation of theimpactor tool 16 relative to any suitable reference plane, axis, etc. Itwill be appreciated that the reference plane, axis, etc. can be separatefrom the patient 19, or in other embodiments, the reference plane, axis,etc. can be associated directly with the anatomy of the patient 19. Forinstance, the surgeon can input the location, orientation, etc. ofcertain anatomical features into a computerized system, and this datacan be used as reference data or as a coordinate system to detect theactual orientation of the impactor tool 16 as will be discussed.

Thus, to implant the acetabular cup 14, the surgeon dislocates the hipjoint of the patient 19, performs any necessary reaming of theacetabulum 17 of the patient 19, and mounts the acetabular cup 14 to theimpactor tool 16 as discussed above. The surgeon also determines thetarget inclination angle θ_(i), and the anteversion angle θ_(a) of theimpactor tool 16. Then, as the surgeon moves the impactor tool 16generally into position to implant the cup 14, the orientation sensor 34detects the actual orientation of the load axis A of the impactor tool16. The orientation feedback device 36 provides one or more feedbacksignals when the load axis A is substantially aligned with thepredetermined target inclination angle θ_(i) and the predeterminedtarget anteversion angle θ_(a). Once the feedback signals are provided,the surgeon knows that the impactor tool 16 is properly oriented, andthe surgeon can begin applying the load F_(i) to the head 20 of theimpactor tool 16, thereby driving the cup 14 into the acetabulum 17 ofthe patient 19.

It will be appreciated that the implanting apparatus 26 can beconfigured to detect any suitable orientation other than the inclinationangle θ_(i) and the anteversion angle θ_(a). Also, it will beappreciated that the orientation feedback device 36 can provide separatefeedback signals for the inclination angle θ_(i) and the anteversionangle θ_(a). Furthermore, the implanting apparatus 26 can store inmemory one or more default target inclination angles θ_(i) and/or targetanteversion angles θ_(a).

Additionally, in some embodiments, the implanting apparatus 26 caninclude various controls for manually setting the target inclinationangle θ_(i) and/or target anteversion angle θ_(a). For instance, theimplanting assembly 10 can include an input device 41 (FIGS. 1 and 4)for manually setting the target orientation of the impactor tool 16.More specifically, the input device 41 can include buttons, dials, adisplay, and other features for setting the target inclination angleθ_(i), the target anteversion angle θ_(a,) or any other setting for theimplanting assembly 10. The input device 41 can be integrally coupled tothe housing 28, and/or the input device 41 can be separate and remotefrom the housing 28 of the apparatus 26. For instance, the input device41 can be in wireless communication with the implanting apparatus 26.For instance, as shown in FIG. 1, the input device 41 can include awireless transmitter 43, and the implanting apparatus 26 can include awireless receiver 45. The receiver 45 receives wireless signals from thetransmitter 43 to thereby set the target orientation of the load axis A.For instance, the input device 41 can include a switch for choosingbetween multiple (e.g., three) different preset target orientations(e.g., a first non-adjustable range, a second non-adjustable range, anda third non-adjustable range). Also, in some embodiments, the inputdevice 41 can include an alphanumeric keypad for manually inputting andsetting a particular target orientation.

Furthermore, in some embodiments, the input device 41 can include theorientation feedback device 36. For instance, the input device 41 caninclude a speaker of the audible feedback device 38 or any othersuitable component of the orientation feedback device 36.

Thus, the implanting apparatus 26 can allow the surgeon to implant theacetabular cup 14 more conveniently and with greater accuracy. It willbe appreciated that the implanting apparatus 26 can provide feedback tothe surgeon before the input load F_(i) is applied and while theacetabular cup 14 is being driven into the acetabulum 17. Accordingly,the acetabular cup 14 can be more easily and accurately placed into thetarget location within the pelvis 15.

However, it can be difficult for the surgeon to know when the acetabularcup 14 is fully seated in the pelvis 15. Thus, the implanting apparatus26 can further include an impact sensor 47 (FIGS. 1, 2 and 4). As willbe described, the impact sensor 47 can detect an actual effect ofimpacting the impactor tool 16. For instance, the impact sensor 47 canbe configured to detect an actual impact force F_(i) on the head 20 ofthe impactor tool 16. Furthermore, the impact sensor 47 can detect anactual displacement of the impactor tool 16 when the load F_(i) isapplied to the head 20. In addition, the impact sensor 47 can detect anactual acoustic effect occurring when the load F_(i) is applied. It willbe appreciated that the impact sensor 47 can be configured to detect anysuitable effect of applying the load F_(i). The impact sensor caninclude any suitable component, such as an accelerometer and/or apiezoelectric sensor, for detecting the actual impact effect. It will beappreciated that the orientation sensor 34 and the impact sensor 47 canrely on the same components, such as a common accelerometer, for therespective functions.

In addition, the implanting apparatus 10 can include an impact feedbackdevice 48 (FIG. 4). Generally, the impact feedback device 48 provides afeedback signal when the actual effect of applying the load F_(i)detected by the impact sensor 47 substantially matches a predeterminedtarget impact effect. More specifically, as will be discussed, thesurgeon can predetermine a target impact effect (e.g., a predeterminedimpact force F_(i), an amount of displacement, an acoustic effect, etc.)that correlates to a condition in which the acetabular cup 14 is fullyseated in the acetabulum 17. Then, the controller 46 can cause theimpact feedback device 48 to provide the respective feedback signal whenthe actual impact effect substantially matches the predetermined targetimpact effect. Thus, the impact feedback device 48 can inform thesurgeon that the acetabular cup 14 has been driven sufficiently deepenough into the acetabulum 17 of the patient 19.

More specifically, when the acetabular cup 14 is driven into theacetabulum 17 and hits cortical bone, the amount of bounce back (i.e.,displacement) of the impactor tool 16 in a direction opposite to thevector of the load F_(i) may change significantly. This predeterminedamount of displacement can be stored in memory as the target impacteffect of applying the load F_(i), and the impact feedback device 48 canprovide the feedback signal when the actual displacement of the impactortool 16 is substantially equal to or exceeds the target displacement,thereby indicating that the acetabular cup 14 has reached the corticalbone of the pelvis 15. Likewise, the target impact effect can be apredetermined threshold amount of force, acoustic effect, or any othersuitable target effect indicative of the acetabular cup 14 impacting thecortical bone. Moreover, in some embodiments, the input device 41 can beused to manually select a preset target impact effect or to manually setan individual target impact effect as discussed above.

It will be appreciated if the impact feedback device 48 can include anysuitable device, such as an audible feedback device 50, a visualfeedback device 52, and/or a tactile feedback device 54. The audiblefeedback device 50 provides an audible feedback signal, and can includea speaker or any other suitable device for providing an audible feedbacksignal. The visual feedback device 52 provides a visual feedback signal,and can include one or more lights, such as LED lights, for providing avisual feedback signal. Also, the tactile feedback device 54 provides atactile feedback signal and can include a vibration motor thatselectively provides a tactile feedback signal.

Thus, referring to FIG. 5, an exemplary embodiment of a method ofimplanting the acetabular cup 14 will be discussed in greater detail.The method 60 begins in block 61, in which the target location of theacetabular cup 14 is determined. More specifically, the surgeon analyzesthe pelvis 15 and other anatomical features of the patient 19 anddetermines where the acetabular cup 14 should be implanted (i.e., thetarget location of the acetabular cup 14) within the acetabulum 17.Block 61 can include selecting a particular inclination angle θ_(i)and/or a particular anteversion angle θ_(a) of the axis A of theacetabular cup 14.

Then, in block 62, the surgeon determines a target orientation for theimpactor tool 16 necessary to drive the acetabular cup 14 into thetarget location determined in block 61. As discussed above, the surgeoncan use the input device 41 to manually input a target orientation forthe impactor tool 16, or the surgeon can use the input device 41 toselect one of the various default target orientations for the impactortool 16. Also, the input device 41 can automatically calculate and setthe target orientation of the impactor tool 16 based on variousparameters input by the surgeon. In some embodiments, the targetorientation can be set to any suitable value(s) for high precision.

Furthermore, in block 64, the surgeon determines a target impact effectfor the impactor tool 16. As discussed above, the input device 41 can beused to set the target impact effect necessary for achieving the targetlocation selected in block 61. Also, the surgeon can use the inputdevice 41 to select one of the various default target impact effects, orthe input device 41 can automatically calculate and set the targetimpact effect based on various parameters input by the surgeon.Moreover, the target impact effect can be set to any suitable value(s)for high precision.

Then, as the surgeon moves the impactor tool 16, it is determined indecision block 66 whether the actual orientation of the load axis A issubstantially equal to or within the predetermined range of the targetorientation set in block 62. If the actual orientation is substantiallyequal to or within the range of the target orientation, then in block70, the orientation feedback device 36 provides the respective feedbacksignal(s) described above. However, if the actual orientation does notsubstantially equal or is outside the range of the target orientation,then in block 68, the surgeon re-orients the impactor tool 16 until theactual orientation is substantially equal to or within the range of thetarget orientation (i.e., decision block 66 answered affirmatively) andthe orientation feedback signal(s) is/are provided.

Then, in block 72, the surgeon begins applying the load F_(i) to thehead 20 of the impactor tool 16. The load F_(i) can be applied with amanual tool, such as a mallet, or an automated tool can be used to applythe load F_(i).

In some embodiments, the surgeon strikes the head 20 of the impactortool 16 repeatedly to progressively drive the cup 14 deeper into theacetabulum 17. Because each impact may cause the impactor tool 16 tomove out of alignment with the target orientation set in block 62, themethod 60 includes decision block 73, wherein it is determined whetherthe load axis A of the impactor tool 16 has moved out of alignment fromthe target orientation. If decision block 73 is answered affirmatively,block 68 follows, and the surgeon reorients the impactor tool 16 untilthe load axis A is substantially aligned with the target orientation.Once the impactor tool 16 is properly reoriented, the feedback signal isagain provided in block 70, and the surgeon can continue to impact thetool 16. However, assuming that the actual orientation of the load axisA remains in alignment with the target orientation set in block 62(i.e., decision block 73 answered negatively), decision block 74follows.

In decision block 74, it is determined whether the actual impact effectsubstantially matches or exceeds a threshold of the target impact effectset in block 64. If the actual impact effect is substantially differentfrom the target impact effect, then block 72 occurs, and the surgeonfurther applies the load F_(i) supplied to the head 20 of the impactortool 16. However, once the impact sensor 47 detects that the actualimpact effect substantially matches or exceeds the target impact effect,then the impact feedback device 48 provides the respective feedbacksignal in block 76, and the surgeon is aware that the cup 14 is in thetarget location predetermined in block 61. It will be appreciated thatthe impact feedback signal can be provided simultaneously with theorientation feedback signal so that the surgeon knows that theacetabular cup 14 is correctly located in the desired target locationwithin the acetabulum 17.

In some embodiments, once the feedback signals have been provided, theycan be manually turned off. For instance, if the feedback signal is alight, then the surgeon has the ability to turn off the light. Thus, thesurgeon has greater control over the feedback signal. Also, if thesurgeon wishes to re-confirm that the impactor tool 16 is properlyoriented or that the acetabular cup 14 is properly seated, the surgeoncan turn off the respective feedback signal and check whether thefeedback signal is provided again.

Accordingly, the implanting assembly 10 provides a convenient andaccurate means for orienting the impactor tool 16 and for implanting theacetabular cup 14. The implanting assembly 10 also ensures that theacetabular cup 14 will be seated in the desired location within thepelvis 15. As such, the prosthetic joint assembly is more likely toprovide adequate support and stability to the patient 19.

Referring now to FIG. 6, another exemplary embodiment of a prosthesisimplantation system 105 is illustrated. As will be discussed in greaterdetail, the system 105 can include various components that are similarto those discussed above. Components that are similar to the embodimentsof FIGS. 1-5 are identified with corresponding reference numeralsincreased by 100. As will be discussed, the system 105 can be a modularkit that facilitates the selection and implantation of a prostheticdevice, such as a prosthetic hip joint.

In some embodiments, the system 105 can include an impactor tool 116 ofthe type discussed above and shown in FIGS. 1 and 2. Also, the system105 can include an implanting apparatus 126 of the type discussed aboveand shown in FIGS. 1 and 2. As such, the implanting apparatus 126 caninclude a housing 128. The housing 128 can be tubular and can include apassage 130 or other type of aperture extending therethrough.Furthermore, the implanting apparatus 126 can include an orientationsensor 134 that is in communication with a controller 146 of the typediscussed above. As stated above, the orientation sensor 134 can includean accelerometer (e.g., a three-axis accelerometer) that, with thecontroller 146, detects an actual orientation of the housing 128relative to a reference point, vector, axis, etc. For instance, in someembodiments, the orientation sensor 134 can detect an actual orientationof the axis A_(A) of the housing 128 relative to a direction of gravity.In other embodiments, the orientation sensor 134 is calibrated in orderto detect the orientation of the axis A_(A) relative to anotherreference system, such as medical equipment used during implantationprocedures (e.g., an examination table, etc.), the patient's anatomy,and the like.

The controller 146 can be embedded and housed within the housing 128.Also, in some embodiments, the controller 146 can be independent of thehousing 128, and the orientation sensor 134 can be in wired or wirelesscommunication with the controller 146. In still other embodiments, somecomponents of the controller 146 can be enclosed within the housing 146and other components of the controller 146 can be independent of thehousing 146.

The controller 146 can include a memory module 149. The memory module149 can be of any suitable type, such as computer-readable random accessmemory (RAM).

Also, the implanting apparatus 126 can include an input device 141. Theinput device 141 can include one or more buttons, switches, etc. thatthe user can press, slide, actuate, or otherwise manipulate forselectively providing a user input. As will be discussed in greaterdetail below, the user can use the input device 141 to cause the actualorientation of the axis A_(A) detected by the orientation sensor 134 tobe stored in the memory module 149. This stored data can be referencedlater as a target orientation of the housing 128 while implanting aprosthetic member.

Additionally, the implanting apparatus 126 can include an orientationfeedback device 136 of the type discussed above in relation to FIGS.1-5. As such, the orientation feedback device 136 can include a visualfeedback device (e.g., one or more LED lights) that emits a visualfeedback signal, an audible feedback device (e.g., an audible alarm)that emits an audible feedback signal, and/or a tactile feedback device(e.g., a vibratory motor) that emits a tactile feedback signal. As willbe discussed, the orientation feedback device 136 can emit therespective feedback signal(s) when the orientation of the axis A_(A)substantially matches the target orientation stored in the memory module149.

As discussed above, the passage 130 can receive the impactor tool 116 tothereby removably couple the implanting apparatus 126 to the impactortool 116. When coupled, the orientation sensor 134 can detect an actualorientation of the impactor tool 116. For instance, the orientationsensor 134 can detect an actual orientation of the axis A_(T) of theimpactor tool 116.

In some embodiments, the implanting apparatus 126 and the impactor tool116 can be coaxial. In other embodiments, the respective axes A_(A),A_(T) can be spaced apart. Also, calibration of the orientation sensor134 may be necessary such that the orientation sensor 134 can be used toaccurately detect the orientation of the impactor tool 116.

Furthermore, the housing 128 of the implanting apparatus 126 and/or theimpactor tool 116 can include a keying feature 171 as shown in FIG. 9.The keying feature 171 allows the housing 128 to be coupled to theimpactor tool 116 only at a known orientation. For instance, theimpactor tool 116 can include a rounded surface 172 and a flat surface174. Similarly, the housing 128 can include a rounded surface 176 and aflat surface 178. The flat surfaces 174, 178 can abuttingly mate suchthat the axis A_(A) is at a known orientation relative to the axisA_(T). It will be appreciated that the housing 128 and impactor tool 116can include any suitable features for keying the housing 128 to theimpactor tool 116 without departing from the scope of the presentdisclosure.

In addition, the housing 128 of the implanting apparatus 126 can includea visual indicator 165. The visual indicator 165 can be of any suitabletype, such as a laser-etched mark or other indicia. The visual indicator165 can allow the user to visually confirm that the housing 128 (andthus the axis A_(A)) is at a known and predetermined orientationrelative, for instance, to the direction of gravity.

The system 105 can further include a plurality of prosthetic members 112a, 112 b, such as prosthetic acetabular cups for a prosthetic hip joint.It will be appreciated that the prosthetic members 112 a, 112 b can beof any suitable type. The prosthetic members 112 a, 112 b can vary insize, structural features, materials, or in any other suitable manner.

In some embodiments, the prosthetic members 112 a, 112 b within thesystem 105 can include a plurality of trial prosthetic members 112 a anda plurality of primary and/or revision prosthetic members 112 b. Thetrial prosthetic members 112 a can each have a primary prosthetic member112 b that corresponds in size, structural features, and the like. Also,as will be discussed, the trial prosthetic members 112 a can be used toselect and prepare for implanting one of the primary prosthetic members112 b. As such, the medical professional can experiment with the trialprosthetic members 112 a to determine which of the primary prostheticmembers 112 b to implant into the patient. Also, with the trialprosthetic member 112 a, the medical professional can determine andselect a target orientation for implanting the primary prosthetic member112 b as will be discussed in greater detail below.

The housing 128 of the implanting apparatus 126 can be removably coupledto each of the trial prosthetic members 112 a. For these purposes, thesystem 105 can include one or more coupling members 180. The couplingmembers 180 can be substantially disc-shaped and can have a variety ofsizes according to sizes of corresponding trial prosthetic members 112a.

The coupling members 180 can removably couple to the trial prostheticmembers 112 a as shown in FIG. 7. For instance, the coupling member 180can be received within the trial prosthetic member 112 a to be coupledthereto. Also, the trial prosthetic member 112 a can include acontinuous groove (not shown) that removably receives the couplingmember 180; however, it will be appreciated that the coupling member 180can be coupled to the trial prosthetic member 112 a in any suitablefashion. Furthermore, the coupling member 180 can be integrally coupledto the trial prosthetic member 112 a so as to be monolithic.

The implanting apparatus 126 can also removably couple to the couplingmember 180. For instance, the implanting apparatus 126 can be threadablycoupled to the coupling member 180 or by a snap fit. In otherembodiments, the implanting apparatus 126 can be integrally coupled tothe coupling member 180 via a breakable joint (not shown), and the usercan manually snap and break the coupling member 180 away from theimplanting apparatus 126. However, it will be appreciated that theimplanting apparatus 126 can be coupled to the coupling member 180 inany suitable fashion.

It will be appreciated that once coupled, the axis A_(A) of theimplanting apparatus 126 can be coaxial with an axis A_(PT) of the trialprosthetic member 112 a as shown in FIG. 7. Thus, by detecting theorientation of the axis A_(A), the orientation sensor 134 can detect theorientation of the axis A_(PT) of the trial prosthetic member 112 a. Inother embodiments, the axis A_(A) can be spaced apart from the axisA_(PT), but because the relative position of the axes A_(A), A_(PT) isknown, the orientation sensor 134 can detect the orientation of the axisA_(PT) when the implanting apparatus 126 is coupled to the trialprosthetic member 112 a.

The implanting apparatus 126 can also be coupled to the primaryprosthetic members 112 b. For instance, as shown in FIG. 8 and similarto the embodiments of FIGS. 1 and 2, the impactor tool 116 can couple toone of the prosthetic members 112 b, and the implanting apparatus 126can removably couple to the impactor tool 116. Also, in someembodiments, the coupling member 180 includes an aperture (not shown)that receives the impactor tool 116 so that the coupling member 180 canremain attached to the implanting apparatus 126 when the implantingapparatus 126 is coupled to the impactor tool 116. It will beappreciated that once coupled, the orientation of the axis A_(A) of theimplanting apparatus 126 is known relative to an axis A_(T) of theimpactor tool 116 and the axis A_(PP) of the primary prosthetic member112 b as shown in FIG. 8. For instance, these axes A_(A), A_(PT), A_(PP)can be substantially aligned. Thus, by detecting the orientation of theaxis A_(A), the orientation sensor 134 can detect the orientation of theaxes A_(PT), A_(PP) as well.

Thus, referring now to FIG. 10, a method of using the system 105 will bediscussed. Beginning in step 182, the medical professional can select atrial prosthetic member 112 a from the plurality of trial prostheticmembers 112 a within the system 105. As stated above, the trialprosthetic member 112 a can be selected according to the size, material,etc. needed for a particular patient and to properly trial the implantrelative to the patient's anatomy.

Then, in step 184, the implanting apparatus 126 can be coupled to theselected trial prosthetic member 112 a. As stated above and as shown inFIG. 7, the implanting apparatus 126 can be coupled to the member 112 avia a corresponding coupling member 180. Also, the implanting apparatus126 can be coupled relative to the trial prosthetic member 112 a suchthat the visual indicator 165 is at a known location, for instance,relative to the direction of gravity. Furthermore, the implantingapparatus 126 can be coupled such that the axis A_(A) of the implantingapparatus 126 is at a known orientation relative to the axis A_(PT) ofthe trial prosthetic member 112 a.

Next, in step 186, the medical professional can determine the targetorientation for subsequently implanting one of the primary prostheticmembers 112 b. For instance, as shown in FIG. 7, the medicalprofessional can manipulate and move the trial prosthetic member 112 aand the attached implanting apparatus 126 relative to a reamedacetabulum 117 of the patient's pelvis 115. As such, the medicalprofessional can find a desired (i.e., target) orientation to be usedwhen implanting the primary prosthetic member 112 b. It will beappreciated that the medical professional can rely on separate measuringdevices or any other means for determining the target orientation.

Once the target orientation has been determined in step 186, step 188follows, and the medical professional can manipulate the input device141 included on the implanting apparatus 126. The orientation of theaxes A_(A), A_(PT) detected at this time is, in turn, transferred intomemory in the memory module 149. Thus, this stored initial orientationis manually inputted by the medical professional and, as will bediscussed, this stored initial orientation represents a targetorientation for use when implanting the primary prosthetic member 112 bwithin the pelvis 115.

Next, in step 190, the implanting apparatus 126 is detached from thetrial prosthetic member 112 a. Also, in step 190, the implantingapparatus 126 is coupled to the primary prosthetic member 112 b. Forinstance, the primary prosthetic member 112 b corresponding to the trialprosthetic member 112 a selected in step 182 can be coupled to theimpactor tool 116, and the implanting apparatus 126 can be coupled tothe impactor tool 116 as well (FIG. 8). It will be appreciated that,once coupled, the orientation sensor 134 can simultaneously detect theorientation of the axis A_(A), the orientation of the axis A_(T), andthe orientation of the axis A_(PP) of the attached prosthetic member 112b.

Then, the medical professional can begin implanting the prostheticmember 112 b. The orientation sensor 134 continuously monitors theactual orientation of the apparatus 126, the impactor tool 116, and theprosthetic member 112 b, and this information is provided to the uservia the feedback device 136. More specifically, in decision block 192,it can be determined whether the actual orientation (i.e., theimplanting orientation) is substantially equal to the target orientationsaved in step 188 based on whether or not the feedback device 136 isemitting its feedback signal. If not, then in step 194, the medicalprofessional knows to re-orient the impactor tool 116. However, once theactual orientation substantially matches the target orientation, thefeedback device 136 provides the feedback signal in step 196. As such,the medical professional knows to start applying a load to the impactortool 116 to drive and implant the prosthetic member 112 b into thepelvis 115.

It will be appreciated that the system 105 can be adapted toadditionally provide feedback when the prosthetic member 112 b hasreached its fully impacted or fully seated position within the pelvis115 as discussed above. For instance, once the prosthetic member 112 breaches cortical bone, the system 105 can provide a correspondingfeedback signal.

Accordingly, the system 105 provides a convenient and accurate means fordetecting and saving a target orientation for the prosthetic member 112bwithin the pelvis 115. The system 105 also conveniently providesfeedback to the medical professional so that the prosthetic member 112 bis properly oriented during implantation. As such, the prosthetic member112 b is more likely to provide adequate support and stability for thepatient over the lifetime of the prosthetic joint.

Moreover, the foregoing discussion discloses and describes merelyexemplary embodiments of the present disclosure. One skilled in the artwill readily recognize from such discussion, and from the accompanyingdrawings and claims, that various changes, modifications and variationsmay be made therein without departing from the spirit and scope of thedisclosure as defined in the following claims. For instance, thesequence of the blocks of the method described herein can be changedwithout departing from the scope of the present disclosure.

1. A surgical instrument for implanting a primary prosthetic member inan anatomical feature based on information gained using a trialprosthetic member, the trial prosthetic member substantiallycorresponding in size and structure to the primary prosthetic member,the surgical instrument comprising: an orientation sensor that detects atrial orientation of the trial prosthetic member, the orientation sensoralso operable to detect an actual orientation of the primary prostheticmember; a memory module; an input device that receives a user input totransfer the trial orientation of the trial prosthetic member detectedby the orientation sensor into the memory module for storage when thetrial orientation corresponds to a target orientation necessary formoving and implanting the primary prosthetic member into engagement withthe anatomical feature; an orientation feedback device that selectivelyprovides an orientation feedback signal to a user; and a controller thatcauses the orientation feedback device to provide the orientationfeedback signal when the actual orientation of the primary prostheticmember detected by the orientation sensor is substantially equal to thetrial orientation stored in the memory module.
 2. A surgical instrumentfor implanting a primary prosthetic member in an anatomical featurebased on information gained using a trial prosthetic member, the trialprosthetic member substantially corresponding in size and structure tothe primary prosthetic member, the surgical instrument comprising: anorientation sensor that detects an initial orientation of the trialprosthetic member when the trial prosthetic member is oriented asdesired relative to the anatomical feature, the orientation sensor alsooperable to detect an implanting orientation of the primary prostheticmember; a memory module; an input device that receives a user input totransfer the initial orientation of the trial prosthetic member detectedby the orientation sensor into the memory module for storage; anorientation feedback device that selectively provides an orientationfeedback signal to a user; a controller that causes the orientationfeedback device to provide the orientation feedback signal when theimplanting orientation of the primary prosthetic member detected by theorientation sensor is substantially equal to the initial orientationstored in the memory module; and a housing that houses the orientationsensor, the housing being removably coupled relative to one of the trialprosthetic member and the primary prosthetic member to position ahousing axis of the housing at a known orientation relative to aprosthesis axis of the one of the trial prosthetic member and theprimary prosthetic member.
 3. The surgical instrument of claim 2,wherein the housing is alternatively and removably coupled relative toboth the trial prosthetic member and the primary prosthetic member. 4.The surgical instrument of claim 2, further comprising an impactor toolthat removably couples to the primary prosthetic member, wherein thehousing removably couples directly to the impactor tool, and furthercomprising a coupling member that removably couples the housing to thetrial prosthetic member.
 5. The surgical instrument of claim 2, furthercomprising an impactor tool that transfers a load along a load axis tothe primary prosthetic member to implant the primary prosthetic member,wherein the impactor tool is removably coupled relative to the primaryprosthetic member to position the load axis at a known orientationrelative to the prosthesis axis, and wherein the housing is removablycoupled to the impactor tool to position the housing axis at a knownorientation relative to both the load axis and the prosthesis axis. 6.The surgical instrument of claim 5, wherein the housing includes a firstportion and a second portion that are hingeably attached so as to have aclam shell construction, and wherein an aperture is defined between thefirst and second portions, the aperture operable to receive the impactortool to removably couple to the impactor tool.
 7. The surgicalinstrument of claim 5, wherein the housing includes a visual indicatorthat indicates a location of the housing axis.
 8. The surgicalinstrument of claim 5, further comprising a keying feature that allowsthe housing to be coupled to the impactor tool only at the knownorientation relative to both the load axis and the prosthesis axis. 9.The surgical instrument of claim 2, wherein the input device is a buttonthat is moveably mounted to the housing.
 10. The surgical instrument ofclaim 1, wherein the orientation sensor includes an accelerometer thatdetects the trial orientation and the actual orientation of theprosthetic member relative to a direction of gravity.
 11. The surgicalinstrument of claim 1, wherein the orientation feedback device includesat least one of a visual feedback device that emits a visual feedbacksignal, an audible feedback device that emits an audible feedbacksignal, and a tactile feedback device that emits a tactile feedbacksignal.
 12. A method of implanting a primary prosthetic member in ananatomical feature based on information gained from a trial prostheticmember that substantially corresponds in size and structure to theprimary prosthetic member, the method comprising: detecting a trialorientation of the trial prosthetic member; saving the trial orientationinto a memory module when the trial orientation corresponds to a targetorientation necessary for moving and implanting the primary prostheticmember into engagement with the anatomical feature as a result ofreceiving a user input; detecting an actual orientation of the primaryprosthetic member; and providing an orientation feedback signal when theactual orientation of the primary prosthetic member is substantiallyequal to the trial orientation saved in the memory module.
 13. A methodof implanting a primary prosthetic member in an anatomical feature basedon information gained from a trial prosthetic member that substantiallycorresponds in size and structure to the primary prosthetic member, themethod comprising: detecting an initial orientation of the trialprosthetic member when the trial prosthetic member is oriented asdesired relative to the anatomical feature; saving the initialorientation into a memory module as a result of receiving a user input;detecting an implanting orientation of the primary prosthetic member;and providing an orientation feedback signal when the implantingorientation of the primary prosthetic member is substantially equal tothe initial orientation; wherein detecting the initial orientation ofthe trial prosthetic member comprises removably coupling a prosthesisimplanting apparatus with an orientation sensor to the trial prostheticmember and detecting the initial orientation of the trial prostheticmember with the orientation sensor, and wherein detecting the implantingorientation comprises removably coupling the prosthesis implantingapparatus to the primary prosthetic member and detecting the implantingorientation of the primary prosthetic member with the orientationsensor.
 14. The method of claim 13, wherein detecting the implantingorientation further comprises removably coupling an impactor tool to theprimary prosthetic member and removably coupling the prosthesisimplanting apparatus to the impactor tool.
 15. The method of claim 14,further comprising impacting the impactor tool to transfer an impactforce via the impactor tool to the primary prosthetic member and todrive the primary prosthetic member toward a target location within apatient.
 16. The method of claim 14, wherein removably coupling theprosthesis implanting apparatus to the impactor tool comprises keyingthe prosthesis implanting apparatus to the impactor tool at a knownorientation relative thereto.
 17. The method of claim 12, furthercomprising receiving the user input due to manipulation of an inputdevice by a user.
 18. The method of claim 12, further comprisingdetecting the trial orientation and the actual orientation of theprosthetic member relative to a direction of gravity.
 19. A prosthesisimplantation system comprising: a trial prosthetic acetabular cupdefining a trial axis; a primary prosthetic acetabular cup defining aprimary axis, the primary prosthetic acetabular cup substantiallycorresponding in size and structure to the trial prosthetic acetabularcup; an impactor tool that removably couples to the primary prostheticacetabular cup and transfers a load along a load axis to implant theprimary prosthetic acetabular cup; and a prosthesis implanting apparatusthat includes: a housing operable to be removably coupled to the trialprosthetic acetabular cup, the housing operable to be alternatively andremovably coupled to the impactor tool; an orientation sensor thatdetects an initial orientation of the trial axis when the housing isremovably coupled to the trial prosthetic acetabular cup and animplanting orientation of the primary axis when the housing is removablycoupled to the impactor tool; a memory module; an input device thatreceives a user input to transfer the initial orientation of the trialaxis detected by the orientation sensor into the memory module forstorage; an orientation feedback device that selectively provides anorientation feedback signal; and a controller that causes theorientation feedback device to provide the orientation feedback signalwhen the housing is coupled to the impactor tool and when the implantingorientation of the primary axis is substantially equal to the initialorientation of the trial axis stored in the memory module.
 20. A methodof implanting a primary prosthetic acetabular cup in an acetabulum basedon information gained from a trial prosthetic acetabular cup thatsubstantially corresponds in size and structure to the primaryprosthetic acetabular cup, the method comprising: removably coupling aprosthesis implanting apparatus with an orientation sensor to the trialprosthetic acetabular cup; detecting an initial orientation of the trialprosthetic acetabular cup with the orientation sensor when the trialprosthetic member is oriented as desired relative to the acetabulum;saving the initial orientation of the trial prosthetic member into amemory module as a result of receiving a user input; removing theprosthesis implanting apparatus from the trial prosthetic acetabularcup; removably coupling an impactor tool to the primary prostheticacetabular cup; removably coupling the prosthesis implanting apparatusto the impactor tool; detecting an implanting orientation of the primaryprosthetic acetabular cup with the orientation sensor when theprosthesis implanting apparatus is removably coupled to the impactortool and the impactor tool is removably coupled to the primaryprosthetic acetabular cup; providing an orientation feedback signal whenthe implanting orientation of the primary prosthetic acetabular cup issubstantially equal to the initial orientation of the trial prostheticmember; and implanting the primary prosthetic acetabular cup at theinitial orientation.
 21. The surgical instrument of claim 1, furthercomprising an impactor tool that removably couples to the primaryprosthetic member, further comprising an impact sensor that detects anactual acoustic effect of impacting the impactor tool, and furthercomprising an impact feedback device that selectively provides an impactfeedback signal, and wherein the controller causes the impact feedbackdevice to provide the impact feedback signal when the actual acousticeffect of impacting the impactor tool detected by the impact sensorsubstantially matches a predetermined target acoustic effect ofimpacting the impactor tool.
 22. The method of claim 12, furthercomprising removably coupling an impactor tool to the primary prostheticmember, removably coupling the prosthesis implanting apparatus to theimpactor tool, automatically detecting an actual acoustic impact effectof impacting the impactor tool, and automatically providing an impactfeedback signal when the actual acoustic impact effect substantiallymatches a predetermined target acoustic impact effect.